Microquasars are black-hole X-ray binaries with relativistic jets that mimic phenomena seen in quasars. I will present recent results on GRS 1915+105 as well as on other microquasars that show the close connection between instabilities in the accretion disk (seen in X-rays) and the ejection of relativistic plasma clouds (seen in radio). The possibility of a connection between these objects and gamma-ray sources is suggested by the association of a possible microquasar with an EGRET source.